1. Field of the Invention
The invention pertains to a thermosetting powder coating composition, optionally in combination with a catalyst.
2. Related Art
Thermosetting powder coating compositions are generally known.
Most powder coatings are based at least in part on the use of an epoxy resin as cross-linking agent. For an example of this reference is made to U.S. Pat. No. 4,147,737. The binder described in said document comprises a mixture composed of 4-25 wt. % of a polyepoxide resin, the molecules of which contain an average of at least two epoxy groups, and 75-96 wt. % of a solid modified polyester resin having an acid number of from 30 to 100 and softening in the range of 60.degree. to 130.degree. C. The epoxy resin preferably employed is triglycidyl isocyanurate (TGIC). In addition, the powder coating may contain a catalyst and, if so desired, an extra cross-linking agent.
A drawback to the known powder coatings is that the substance employed as cross-linking agent, triglycidyl isocyanurate (TGIC), is toxicologically suspect.